There is a strong male predominance of esophageal adenocarcinoma, which might be related to the higher prevalence of precursor lesions such as erosive reflux esophagitis in men compared with women.

Dr Katsunori Iijima and colleagues from Japan investigated the gender difference in a reflux esophagitis model of rats, and explored the potential role of estrogen in controlling esophageal tissue damage.

An acid-reflux oesophagitis model was surgically produced in male and female rats, and ascorbic acid in the diet and sodium nitrite in the drinking water were administered to half of either group to provoke luminal exogenous nitric oxide as an exacerbating agent.

The team reported that 7 days after the surgery, the esophagus was excised, and the injury area, myeloperoxidase activity and pro-inflammatory cytokine levels were measured.

While there was no gender difference in esophageal damage in the baseline model, the team found that esophageal damage was more intensively observed in males than in females in the presence of exogenous nitric oxide administration.

While esophageal damage was increased in ovariectomized rats compared with sham ovariectomized, exacerbated esophageal damage was attenuated by the replacement of 17β-estradiol.

The reearch team observed that exacerbated esophageal damage in male rats was suppressed by 17β-estradiol.

Dr Iijima's team concludes, "This is the first study showing the prominent gender difference in the severity of esophageal tissue damage in a gastro-esophageal reflux disease-related animal model, highlighting the critical involvement of estrogen in controlling gastro-esophageal reflux disease-related esophageal epithelial injury."